A catheter bending fatigue tester

Abstract

The application discloses a catheter bending fatigue testing machine, which comprises a supporting seat, a rotary driver and a loading part. The loading part comprises a first screw linear displacement mechanism, a connecting part and a locking screw. The first guide mechanism is connected with the output shaft of the rotary driver, and the displacement direction of the first follower is perpendicular to the axial direction of the output shaft. The connecting part is provided with a first through hole matched with the catheter. One end of the catheter in the axial direction is sleeved in the first through hole, and the other end in the axial direction is rotationally connected with the mounting part. One end of the locking screw penetrates through the connecting part and the first follower in sequence and abuts against the first guide mechanism. The locking screw is threadedly connected with the through hole penetrating through the connecting part and / or the first follower. Compared with the prior art, the application can realize continuous fine adjustment of radial load, the regulation and control of local bending are more accurate, and the test accuracy can be improved.

Description

Technical Field

[0001] This application relates to the field of mechanical property testing technology for rotating components, specifically to a conduit bending fatigue testing machine. Background Technology

[0002] Rotational bending fatigue testing is a test method for determining the fatigue properties of metallic materials. The test involves rotating the specimen to withstand bending moment until it fractures or reaches a predetermined number of cycles. It can be used to evaluate the fatigue limit, crack propagation rate, and other properties of metallic components.

[0003] Traditional rotary bending fatigue testing mechanisms, such as those described in patent document CN113252477A, ​​suspend weights at the ends of the specimen as radial load loading mechanisms, applying the radial load using the weight's gravity. However, this loading method relies entirely on the fixed weight of the weights to apply the radial load. Load adjustment requires replacing standard weights of different specifications, and the minimum adjustment accuracy is limited by the smallest division of the weights. For example, a common standard weight has a minimum division of 1g, corresponding to a load increment of approximately 0.01N. For testing scenarios requiring precise control of bending stress, such as low-stress fatigue testing and material fatigue limit calibration, this step-by-step approach prevents continuous fine-tuning of the radial load, easily leading to deviations between the actual applied bending stress and the preset value, directly affecting the accuracy and repeatability of fatigue life data. Utility Model Content

[0004] Therefore, this application provides a conduit bending fatigue testing machine to solve the problem that existing rotary bending fatigue testing devices cannot continuously fine-tune the magnitude of the applied radial load.

[0005] To achieve the above objectives, this application provides the following technical solution: A conduit bending fatigue testing machine, comprising: The support base is provided with a mounting part; A rotary driver for driving its output shaft to rotate about a first linear axis; The loading component includes a first lead screw linear displacement mechanism, a connecting part, and a locking screw. The first lead screw linear displacement mechanism includes a first driven member and a first guide mechanism. The first guide mechanism is connected to the output shaft. The displacement direction of the first driven member is perpendicular to the first straight line. The connecting part has a first through hole that matches the conduit. One axial end of the conduit is sleeved in the first through hole and is detachably fixedly connected to the first through hole or the first driven member. The other axial end is detachably rotatably connected to the mounting part, and the rotation axis is consistent with the axis of the output shaft. The axis of the locking screw is consistent with the axis of the output shaft. The end of the locking screw away from its head passes through the connecting part and the first driven member in sequence and then abuts against the first guide mechanism. The locking screw is threadedly connected to the through hole that passes through the connecting part and / or the first driven member.

[0006] Optionally, the first lead screw linear displacement mechanism includes: The first active component is a first screw with a drive slot at its head. A first rotating seat is connected to the output shaft. The first rotating seat has a preset cavity. A first opening and a second opening are respectively opened at opposite ends of the preset cavity. The head of the first screw is located in the preset cavity, and the other end passes through the first opening and is threadedly connected to the first driven member. A rotational clearance is provided between the first screw and the inner wall of the first opening. The second opening is arranged opposite to the drive slot. When viewed along the axial direction of the first screw, the second opening is located in the closed area of ​​the head, and the drive slot is located in the closed area of ​​the second opening.

[0007] Optionally, the first rotary seat is connected to the output shaft via the first guide mechanism.

[0008] Optionally, the first driven member is provided with a receiving cavity with one end open, the receiving cavity matching the conduit, one end opening of the receiving cavity being disposed opposite to the first perforation along a first straight line direction, and one axial end of the conduit passing through the first perforation and then entering the receiving cavity.

[0009] Optionally, the loading element further includes: The movable screw has a second guide rail provided in the first guide mechanism. The end of the movable screw away from its head passes through the connecting part and the first driven member in sequence and then passes through the second guide rail. The movable screw is threadedly connected to the through hole of the connecting part and / or the first driven member. The movable screw is slidably connected to the second guide rail, and the sliding direction is consistent with the sliding direction of the first driven member.

[0010] Compared with the prior art, the loading component of this application can apply a radial load to one axial end of the catheter, and the magnitude of the radial load can change continuously, rather than increasing or decreasing in leaps and bounds by multiples of the minimum weight. This allows for more precise control of the catheter bending deformation and improves the accuracy of the test. Attached Figure Description

[0011] To more intuitively illustrate the prior art and this application, several exemplary figures are provided below. It should be understood that the specific shapes and structures shown in the figures should not generally be regarded as limiting conditions for implementing this application; for example, based on the technical concept disclosed in this application and the exemplary figures, those skilled in the art are able to easily make conventional adjustments or further optimizations to the addition / reduction / classification, specific shapes, positional relationships, connection methods, size ratios, etc. of certain units (components).

[0012] Figure 1 A schematic diagram of the structure of a 600-degree conduit bending fatigue testing machine provided in one embodiment of this application; Figure 2 for Figure 1 Left-side stereoscopic view of the embodiment; Figure 3 for Figure 2 A magnified view of a portion of the image; Figure 4 for Figure 1 Right-side stereoscopic view of the embodiment; Figure 5 for Figure 1 Side perspective view of the embodiment; Figure 6 for Figure 1 A schematic diagram of the structure of the loading element 500 provided in the embodiment; Figure 7 for Figure 6 Side view perspective structural diagram of the embodiment; Figure 8 for Figure 6 A bottom-view perspective view of the embodiment; Figure 9 for Figure 6 Top view of the embodiment; Figure 10 for Figure 6 A schematic diagram of the fourth guide mechanism provided in the embodiment; Figure 11 for Figure 6 A schematic diagram of the structure of the second slider 513 provided in the embodiment; Figure 12 for Figure 6 A schematic diagram of the structure of the fourth rotary seat provided in the embodiment; Figure 13 for Figure 12A structural diagram of the back side; Figure 14 for Figure 6 A schematic diagram of the structure of the fourth follower provided in the embodiment; Figure 15 for Figure 6 A schematic diagram of the structure of the fourth follower provided in the embodiment; Figure 16 for Figure 6 A schematic diagram of the structure of the connecting part 550 provided in the embodiment; Explanation of reference numerals in the attached figures: Rotary driver 100, output shaft 110, support base 200, mounting part 300, handle 310, oil filling platform 410, pressure testing device 420, loading member 500, first guide mechanism 510, first guide rail 511, second guide rail 512, second slider 513, first rotating seat 520, preset cavity 521, first opening 522, second opening 523, first driven member 530, receiving cavity 531, first screw 540, drive slot 541, connecting part 550, first through hole 551, locking screw 560, moving screw 570, conduit 600. Detailed Implementation

[0013] The present application will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0014] In the description of this application: unless otherwise stated, "a plurality of" means two or more. The terms "first," "second," "third," etc., in this application are intended to distinguish the objects referred to and do not have any special meaning in terms of technical connotation (e.g., they should not be construed as an emphasis on importance or order). Expressions such as "including," "comprising," and "having" also mean "not limited to" (certain units, components, materials, steps, etc.).

[0015] The terms used in this application, such as "upper," "lower," "left," "right," and "middle," are generally used to facilitate intuitive understanding by referring to the accompanying drawings, and are not absolute limitations on the positional relationships in the actual product. Changes in these relative positional relationships, without departing from the technical concept disclosed in this application, should also be considered within the scope of this application.

[0016] This application provides a duct 600 bending fatigue testing machine, including a support base 200, a rotary driver 100, and a loading member 500. The support base 200 has a mounting portion 300; the rotary driver 100 drives its output shaft 110 to rotate around a first linear axis; the loading member 500 includes a first lead screw linear displacement mechanism, a connecting portion 550, and a locking screw 560.

[0017] The first lead screw linear displacement mechanism includes a first driven member 530 and a first guide mechanism 510. The first guide mechanism 510 is connected to the output shaft 110. The displacement direction of the first driven member 530 is perpendicular to the first straight line. The connecting part 550 has a first through hole 551 that matches the guide tube 600. One axial end of the guide tube 600 is sleeved in the first through hole 551 and is detachably fixedly connected to the first through hole 551 and / or the first driven member 530 (preferably with a transition fit or a small interference fit). The other axial end is detachably rotatably connected to the mounting part 300, and the rotation axis is consistent with the axis of the output shaft 110. The axial direction of the locking screw 560 is consistent with the axis of the output shaft 110. The end of the locking screw 560 away from its head (also called the threaded end of the locking screw 560) passes through the connecting part 550 and the first driven member 530 in sequence and then abuts against the first guide mechanism 510. The locking screw 560 is threadedly connected to its through-connection portion 550 and / or the first driven member 530. The threaded connection has a certain degree of self-locking property; therefore, as long as the locking screw 560 is not rotated and remains through-connected, the locking screw 560 can remain stationary relative to both, and the first driven member 530 and the connection portion 550 can be synchronously displaced. "Abutting" refers to the physical contact between the surfaces of two components, where a definite force is applied or borne by each other. In this application, "abutting" means that, based on the contact between the locking screw 560 and the first guide mechanism 510, the locking screw 560 is rotated to bring its head closer to the first guide mechanism 510, thereby applying a force perpendicular to the sliding direction of the first driven member 530 to the first guide mechanism 510 using the locking screw 560 on the first driven member 530, forming a frictional force that resists the sliding of the first driven member 530.

[0018] As is well known, all lead screw linear displacement mechanisms include a driving member, a driven member, a rotary seat for rotating the driving member, and a guiding mechanism that restricts the rotation of the driven member and guides the driven member to move linearly along the thread axis. This is an inherent structure of lead screw linear displacement mechanisms. For ease of understanding, only the differences from the inherent structure are described; the inherent structural parts without structural improvements are not elaborated upon and should not be construed as lacking relevant components in this application. In other words, the first lead screw linear displacement mechanism provided in this application includes a first driving member, a first driven member 530, a first rotary seat 520, and a first guiding mechanism 510. Furthermore, the structure of each component and their mutual cooperation are also inherent structures of lead screw linear displacement mechanisms and will not be elaborated upon in this application.

[0019] A sliding clearance needs to be provided between the first driven member 530 and the first guide mechanism 510 of the first lead screw linear displacement mechanism to allow the first driven member 530 to slide on the first guide mechanism 510. This is an inherent structure of the lead screw linear displacement mechanism and will not be elaborated upon in this application. In this embodiment, a locking screw 560 is provided on the first driven member 530. Tightening the locking screw 560 so that its threaded end abuts against the first guide mechanism 510 applies pressure perpendicular to the sliding direction of the first driven member 530 to the first guide mechanism 510, forming a frictional force that resists the sliding of the first driven member 530 and locks the sliding displacement of the first driven member 530. Loosening the locking screw 560 so that its threaded end contacts the first guide mechanism 510 without force, or directly leaves the first guide mechanism 510, canceling the increased frictional force due to the abutment, allows the first driving member to be rotated, and the first driven member 530 can slide normally on the first guide mechanism 510.

[0020] In this embodiment, the first guide mechanism 510 and the first rotating seat 520 are fixed on the output shaft 110. The connecting part 550 and the first driven member 530 are synchronously displaced, and the displacement direction is the rotational radial direction of the output shaft 110. Therefore, the displacement of the first driven member 530 can drive the axial end of the conduit 600 within the first perforation 551 (or within the first perforation 551 and the accommodating cavity 531 if the first driven member 530 has an accommodating cavity 531) to shift radially. In other words, compared with the prior art, the loading member 500 of this application can apply a radial load to an axial end of the conduit 600, causing the axial end of the conduit 600 to undergo local bending deformation.

[0021] This application utilizes a rotary actuator 100 to rotate a bent and deformed conduit 600 to test its fatigue performance under multiple rotations in a bent state. Failure detection can be performed using an external mechanism or by the failure detection device built into the conduit 600 bending fatigue testing machine. This application does not specifically limit the type of failure detection; it can be real-time dynamic monitoring, such as the real-time oil supply and pressure measurement oil injection platform 410 described later, or offline fixed-point analysis of failure details, stopping rotation after a preset number of rotations to test whether the conduit 600 has failed. Failure detection methods can be macroscopic physical performance monitoring, such as supplying oil to the sealed conduit 600 and measuring oil pressure; microscopic morphology monitoring, such as microscopic or electron microscopic examination of microcracks; or non-destructive testing, such as ultrasonic testing of internal cracks, magnetic particle or penetrant testing of surface cracks, etc. These are standard settings for rotary bending fatigue testing and will not be elaborated upon in this application. In one possible implementation, the first driving member is a first screw 540 with a drive slot 541 at its head; a first rotating seat 520 is connected to the output shaft 110, and the first rotating seat 520 has a preset cavity 521. The preset cavity 521 has a first opening 522 and a second opening 523 at opposite ends. The head of the first screw 540 is located inside the preset cavity 521, and the other end passes through the first opening 522 and is threadedly connected to the first driven member 530. A rotational clearance is provided between the first screw 540 and the inner wall of the first opening 522. The second opening 523 is positioned opposite the drive slot 541. Viewed along the axial direction of the first screw 540, the second opening 523 is located within the closed area of ​​the head, and the drive slot 541 is located within the closed area of ​​the second opening 523. In other words, the drive slot 541 is located within the opening range of the second opening 523, and the outer edge of the head is outside the opening range of the second opening 523. The drive slot 541 is smaller than the second opening 523, allowing the screwdriver to be inserted through the second opening 523 and engaged in the drive slot 541 to drive the first screw 540 to rotate. The head is larger than the second opening 523, so it is limited by the side wall forming the second opening 523 and cannot come out of the second opening 523. This prevents the first screw 540 from flying out and falling off axially during high-speed rotation with the output shaft 110, thus improving safety.

[0022] In one possible implementation, the first rotary seat 520 is connected to the output shaft 110 via a first guide mechanism 510. The first rotary seat 520 is fixedly connected to the first guide mechanism 510 via a first screw 540. One end of the first screw 540 passes sequentially through the first rotary seat 520 and the first guide mechanism 510, and the first screw 540 is threadedly connected to a through-hole in the first rotary seat 520 and / or the first guide mechanism 510. The location of the through-hole is shown below. Figure 12 , Figure 13 The perforation positions on both sides of the preset cavity 521.

[0023] In one possible implementation, the first follower 530 has a receiving cavity 531 with one open end. The receiving cavity 531 matches the conduit 600. One open end of the receiving cavity 531 is positioned opposite to the first through hole 551 along a first straight line direction. One axial end of the conduit 600 passes through the first through hole 551 and then enters the receiving cavity 531. The axial end of the conduit 600 is located in the receiving cavity 531. The receiving cavity 531 can be a mounting groove with one open end or a second through hole with open ends opposite each other.

[0024] In one possible implementation, the loading member 500 further includes a movable screw 570. The first guiding mechanism 510 is provided with a first guide rail 511. The first driven member 530 is slidably connected to the first guide rail 511, and the sliding direction is consistent with the rotational axis of the driving member. This is an inherent structure of the lead screw linear displacement mechanism and will not be elaborated here. In addition to the first guide rail 511, the first guiding mechanism 510 also provides a second guide rail 512. The end of the movable screw 570 opposite to its head passes through the connecting part 550, the first driven member 530, and then into the second guide rail 512. The movable screw 570 is threadedly connected to the through-hole of the connecting part 550 and / or the first driven member 530. The movable screw 570 is slidably connected to the second guide rail 512, and the sliding direction is consistent with the sliding direction of the first driven member 530.

[0025] Optionally, a second slider 513 is provided within the second guide rail 512. The second slider 513 has a second threaded hole that matches the moving screw 570. The end of the moving screw 570 facing away from its head passes through the connecting part 550 and the first driven member 530 in sequence before entering the second guide rail 512 and threadedly connecting to the second threaded hole. That is, one end of the moving screw 570 is slidably connected to the second guide rail 512 through the second slider 513, and the sliding direction of the second slider 513 within the second guide rail 512 is consistent with the sliding direction of the first driven member 530 within the first guide rail 511.

[0026] Optionally, the second guide rail 512 is a guide cavity in the shape of a waist-shaped cylinder, with an opening at the bottom surface and the outer edge of the opening coinciding with the outer edge of the bottom surface. It should be noted that the waist-shaped cylinder is a straight cylinder with a waist-shaped bottom and top surface (also called a racetrack shape, oblong hole, etc., a closed planar figure composed of a rectangle and two semicircles of equal radius, where the width of the rectangle is the same as and coincides with the diameter of the semicircles). The second slider 513 is also a waist-shaped cylinder, and the radius of its waist shape matches that of the guide cavity to form a small sliding gap between the second slider 513 and the inner wall of the guide cavity. The longer side of the rectangle in the waist shape of the second slider 513 is smaller than the longer side of the rectangle in the waist shape of the guide cavity; the difference is the maximum sliding distance preset for the guide rail. The second slider 513 slides along the length of the rectangle in the waist shape of the guide cavity.

[0027] In one possible implementation, the duct 600 bending fatigue testing machine also includes a failure detection device, a dial gauge, and a strain measurement device.

[0028] The output shaft 110 is equipped with a dial indicator, which is fixedly connected to the output shaft 110. Preferably, the connection is detachable. For example, the dial indicator's mounting base can be magnetically attached to the stationary side wall of the rotary driver 100, or it can be clamped or bolted. The key is to ensure that the dial indicator's mounting base and its mounting position remain relatively stationary and fixed in the connected state, preventing easy detachment due to slight interaction between the probe and the measured structure. The dial indicator's probe contacts the mounting portion 300 to detect the radial offset of the mounting portion 300 along the output shaft 110. Specifically: The mounting section 300 is equipped with a bearing for rotatable connection to one end of the guide tube 600. The outer surface of the mounting section 300 is cylindrical and coaxial with the bearing. Adjust the position of the mounting section 300 so that the bearing axis coincides with the first straight line. Use a dial indicator to check if the mounting section 300 is accurately positioned. First, place the dial indicator head (i.e., the probe) on the mounting section 300 and observe the dial reading. Rotate the output shaft 180° and 90° and stop to observe the dial reading again. Check if the data fluctuation is within the allowable ±0.05 deviation range. If it exceeds the range, continue to adjust the position of the mounting section 300 until it is qualified. If the outer wall of the mounting section 300 is irregular, the dial indicator head can be placed on the bearing of the mounting section 300, as long as the axis of the bearing and the output shaft 110 can be aligned as much as possible within the allowable error range.

[0029] The failure detection mechanism is used to detect the failure characteristics of the conduit 600 and characterize the fatigue failure state of the conduit 600; the strain gauge of the strain measuring device is attached to the outer surface of the end of the conduit 600 near the mounting part 300, the length direction of the strain gauge is consistent with the axial direction of the conduit 600, and a gap is provided between the strain gauge and the axis of the conduit 600 along the offset direction of the mounting part 300.

[0030] One end of the conduit 600 is rotatably connected to the mounting part 300. Strain gauges are attached to the conduit 600. After radially offsetting the mounting part 300, the other end of the conduit 600 is connected to the output shaft 110. At this time, the conduit 600 is in an overall eccentric installation state. Subsequently, a radial load is applied to simulate bending. Then, the bent conduit 600 is driven by the rotary actuator 100 to rotate continuously in this eccentric installation state. The failure characteristics of the conduit 600 are detected by a failure detection mechanism to determine whether the conduit 600 has failed and to determine the fatigue life of the conduit 600.

[0031] Due to the necessary assembly clearances of each component, and the influence of factors such as micro-displacement, deformation, wear, or loosening of each component under rotational load, the mounting part 300, which was originally locked and positioned by the first drive device, will experience a slight offset. Therefore, in the rotational fatigue test of the eccentrically mounted conduit 600, there is a risk that the actual radial offset of one end of the conduit 600 will gradually decrease during rotation. The reduction in the measured offset leads to a decrease in actual stress, a slower fatigue damage rate, and an extended fatigue life. However, if the measurement result is still taken as the fatigue life obtained under a fixed offset, the fatigue life of the conduit 600 will be overestimated, resulting in the risk of premature breakage of the conduit 600 during use. In order to control the change in offset during rotation within an acceptable deviation range, this application adds a strain gauge, specifically: Before the conduit 600 rotates, strain gauges monitor the local tensile deformation state of the conduit 600 under these conditions. The original state is observed, with bending deformation occurring at the other end of the conduit 600 along its axial direction, and cracks also occurring at the other end, outside the measurement range of the strain gauges. During rotation, if the offset of the mounting part 300 decreases, the tension caused by its eccentricity decreases, the tensile deformation decreases, and the strain gauge data decreases. If the decrease exceeds the deviation range, rotation can be stopped, and the mounting platform position can be readjusted using the first drive device until the strain gauge data returns to its original state or its data deviation returns to the deviation range, before restarting rotation.

[0032] One end of the output shaft 110 simulates radial bending deformation caused by misalignment between the downstream connector and the rotation axis of the rotating shaft system. The upstream connector of the conduit 600 may be aligned with the rotation axis, but may also be difficult to align completely due to factors such as equipment installation reference deviation and cumulative assembly errors of multiple components. This application uses a mounting platform to simulate the downstream connector. With the assistance of a dial indicator, the position of the mounting platform can be adjusted to align the bearing (and the rotary connector for injecting fluid) with the rotation axis of the output shaft 110, simulating the working condition where the downstream connector is aligned with the rotation axis of the rotating shaft system. Furthermore, the mounting platform can be radially offset using a first drive device to simulate the working condition where the downstream connector is offset, and a rotational bending fatigue test can be performed under this condition. The test results are more accurate and can reduce the operational risks of related equipment.

[0033] In one possible implementation, the failure detection device includes a fluid supply device and a pressure testing device 420. This application does not limit the specific fluid supplied by the fluid supply device; it can be flexibly configured according to the type of conduit 600. If the rotating sample is an oil conduit 600, an oil injection platform 410 is used, and the supplied fluid is oil. If the rotating sample is a gas conduit, a corresponding gas supply device is used, and the supplied fluid is gas. Alternatively, the rotating bending fatigue testing device for the conduit 600 can be equipped with two types of fluid supply devices, both detachably connected via rotary joints. The output end of the fluid supply device corresponding to the type of conduit 600 being measured is sealed and connected to the conduit 600. The output end of the fluid supply device passes through a mounting base and is sealed and connected to one axial end of the conduit 600, while the other axial end of the conduit 600 is sealed. The pressure monitoring device is used to monitor the fluid pressure at the output end of the fluid supply device.

[0034] Once fatigue failure causes cracks in the originally closed fluid channel, fluid leaks out, causing a drop in oil / gas pressure. Pressure monitoring is used to detect fluid leakage, thereby determining whether the conduit 600 has failed due to bending loads and rotational fatigue. In one possible implementation, the fluid supply device is an oil filling platform 410, with its filling port sealed to the axial opening of the conduit 600 mounted on the mounting portion 300. Preferably, the axial end of the conduit 600 is rotatably connected to the mounting portion 300, and the tubular opening at this end of the conduit 600 is sealed to one end of a connecting channel in the mounting portion 300. The filling port of the oil filling platform 410 is sealed to the other end of the connecting channel. That is, the filling port is indirectly sealed to one end of the conduit 600 through the connecting channel of the mounting portion 300. It should be noted that the rotating conduit 600 and the stationary fluid supply device output / installation part 300 are connected by a well-sealed rotary joint, which is an inherent structure of the rotating sample and the stationary device in the rotating bending fatigue testing equipment, and will not be described in detail in this application.

[0035] In one possible implementation, the dial indicator probe is also used to contact the first follower 530 to detect the radial offset of the first follower 530 along the output shaft 110. Measuring the offset of a slider with a dial indicator is a standard setting and will not be elaborated here. Optionally, the end of the first follower 530 extending out of the first guide rail 511 is cylindrical and coaxial with the cylindrical first through hole 551, and the first guide mechanism 510 is cylindrical and coaxial with the cylindrical receiving cavity 531. The cylindrical radii of the first follower 530 and the first guide mechanism 510 are equal. The probe rotates a certain angle on the outer cylindrical radial wall of the first follower 530 and measures the offset in that arc. If the offset is too high, the position of the first follower 530 is adjusted until the offset is acceptable, and the first follower 530 is reset as much as possible so that the first through hole 551 and the receiving cavity 531 are aligned, which facilitates the installation of the conduit 600.

[0036] In one possible implementation, the second drive device includes a second lead screw linear displacement mechanism. The mounting part 300 is connected to the support base 200 via the second lead screw linear displacement mechanism. The mounting part 300 is also connected to the driven member of the second lead screw linear displacement mechanism. The linear displacement direction of the second lead screw linear displacement mechanism is perpendicular to the first linear axis. Optionally, one axial end of the driving lead screw of the second lead screw linear displacement mechanism is provided with a wheel as a handle 310, allowing manual driving of the mounting part 300.

[0037] Optionally, the second drive device further includes a third lead screw linear displacement mechanism. The second lead screw linear displacement mechanism is connected to the mounting base via the third linear displacement mechanism. Specifically, in the second / third lead screw linear displacement mechanism, its driving member rotates on its rotating seat. The rotating seat of the second lead screw linear displacement mechanism is connected to the driven member of the third lead screw linear displacement mechanism. The rotating seat of the third linear displacement mechanism is connected to the mounting base. The driving member of the third linear displacement mechanism is provided with a handle 310 (preferably a rotating wheel). The moving direction of the driven member of the second lead screw linear displacement mechanism is perpendicular to that of the third lead screw linear displacement mechanism, and both are perpendicular to the first linear axis.

[0038] In one possible implementation, there are two or more strain gauges, and the two or more strain gauges are spaced apart along the offset direction of the mounting portion 300. Preferably, this application provides two strain gauges, located at opposite ends of the conduit 600 along the offset direction of the mounting portion 300, at the end with the largest and smallest rotation radii.

[0039] This application does not specify the connection method between the strain gauge rotating with the guide tube 600 and the stationary strain gauge for observing the measurement results. As long as an electrical connection can be achieved to complete communication, it is acceptable. This is an inherent structure of strain gauges for measuring the strain of rotating components, and this application will not elaborate on it. For example, the strain gauge can be wirelessly connected to the strain gauge, unaffected by the rotation of the component. Alternatively, the strain gauge can be connected to the strain gauge via an electrical slip ring. The operation of changing the strain gauge and reconnecting the strain gauge when testing different guide tubes 600 is also a conventional and inherent mechanism of strain measurement devices, and this application will not elaborate on it either, nor should it be construed as a limitation of this application.

[0040] The technical features of the above embodiments can be combined in any way (as long as there is no contradiction in the combination of these technical features). For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described; these embodiments not explicitly written should also be considered to be within the scope of this specification.

[0041] The present application has been described in a relatively specific and detailed manner above through general descriptions and specific embodiments. It should be understood that, based on the technical concept of the present application, several conventional adjustments or further innovations can be made to these specific embodiments; however, as long as they do not depart from the technical concept of the present application, the technical solutions obtained by these conventional adjustments or further innovations also fall within the protection scope of the claims of the present application.

Claims

1. A conduit bending fatigue testing machine, characterized in that, include: The support base is provided with a mounting part; A rotary driver for driving its output shaft to rotate about a first linear axis; The loading component includes a first lead screw linear displacement mechanism, a connecting part, and a locking screw. The first lead screw linear displacement mechanism includes a first driven member and a first guide mechanism. The first guide mechanism is connected to the output shaft. The displacement direction of the first driven member is perpendicular to the first straight line. The connecting part has a first through hole that matches the conduit. One axial end of the conduit is sleeved in the first through hole and is detachably fixedly connected to the first through hole or the first driven member. The other axial end is detachably rotatably connected to the mounting part, and the rotation axis is consistent with the axis of the output shaft. The axis of the locking screw is consistent with the axis of the output shaft. The end of the locking screw away from its head passes through the connecting part and the first driven member in sequence and then abuts against the first guide mechanism. The locking screw is threadedly connected to the through hole that passes through the connecting part and / or the first driven member.

2. The conduit bending fatigue testing machine according to claim 1, characterized in that, The first lead screw linear displacement mechanism includes: The first active component is a first screw with a drive slot at its head. A first rotating seat is connected to the output shaft. The first rotating seat has a preset cavity. A first opening and a second opening are respectively opened at opposite ends of the preset cavity. The head of the first screw is located in the preset cavity, and the other end passes through the first opening and is threadedly connected to the first driven member. A rotational clearance is provided between the first screw and the inner wall of the first opening. The second opening is arranged opposite to the drive slot. When viewed along the axial direction of the first screw, the second opening is located in the closed area of ​​the head, and the drive slot is located in the closed area of ​​the second opening.

3. The conduit bending fatigue testing machine according to claim 2, characterized in that, The first rotating seat is connected to the output shaft via the first guide mechanism.

4. The conduit bending fatigue testing machine according to claim 1, characterized in that, The first driven member has a receiving cavity with one end open. The receiving cavity matches the conduit. One end of the receiving cavity is positioned opposite to the first perforation along a first straight line direction. One axial end of the conduit passes through the first perforation and then enters the receiving cavity.

5. A conduit bending fatigue testing machine according to claim 1, characterized in that, The loading component also includes: The movable screw has a second guide rail provided in the first guide mechanism. The end of the movable screw away from its head passes through the connecting part and the first driven member in sequence and then passes through the second guide rail. The movable screw is threadedly connected to the through hole of the connecting part and / or the first driven member. The movable screw is slidably connected to the second guide rail, and the sliding direction is consistent with the sliding direction of the first driven member.

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